Glena

Habitat varies by species: Glena mielkei occurs in shrubland vegetation of the Azapa valley in northern Chile, associated with Asteraceae host plants. Glena bipennaria bipennaria has been documented in commercial plantations of African mahogany (Khaya spp.) in Brazil. Other species likely occupy diverse terrestrial habitats across their geographic ranges, but specific habitat data for most species is not available.

Primarily distributed in the Americas. Documented occurrences include: United States, Mexico, Central America, South America (Brazil, Chile, Peru, Ecuador, Colombia), and the Caribbean. Glena mielkei is restricted to northern Chile (Azapa valley). Glena bipennaria bipennaria is reported from Brazil in association with introduced African mahogany plantations.

Seasonal development patterns have been documented for Glena bipennaria bipennaria in Brazil, though specific timing details are not provided in available sources. Seasonality for other species is not well documented.

Larval feeding habits vary by species. Glena mielkei larvae feed on Asteraceae species: Trixis cacalioides, Pluchea chingollo, and Tessaria absinthioides; unable to develop on Grindelia tarapacana or Baccharis salicifolia. Glena bipennaria bipennaria feeds on foliage of African mahogany species (Khaya grandifoliola, Khaya senegalensis). Diet for remaining species is not documented.

• Trixis cacalioides - larval host plantAsteraceae; suitable host for Glena mielkei
• Pluchea chingollo - larval host plantAsteraceae; suitable host for Glena mielkei
• Tessaria absinthioides - larval host plantAsteraceae; suitable host for Glena mielkei
• Khaya grandifoliola - larval host plantAfrican mahogany; host for Glena bipennaria bipennaria in Brazil
• Khaya senegalensis - larval host plantAfrican mahogany; host for Glena bipennaria bipennaria in Brazil

Complete metamorphosis with egg, larva, pupa, and adult stages. Larvae of Glena mielkei collected from field and successfully reared to adults in laboratory conditions on suitable host plants. Larvae of Glena bipennaria bipennaria cause defoliation damage as caterpillars. Specific details on pupation sites, adult longevity, and oviposition behavior are not available for most species.

Larvae of Glena bipennaria bipennaria are defoliating caterpillars and were the dominant defoliator in all examined stands of African mahogany in Brazil. Glena mielkei exhibits host plant specificity with a narrow range of suitable hosts; larvae starve or die within days when placed on unsuitable host plants. Outbreak potential of Glena bipennaria bipennaria remains uncertain—it is unclear whether observed infestations represent isolated incidents or will become more frequent.

Herbivorous insects with variable ecosystem impacts. Glena mielkei functions as a specialist herbivore dependent on native vegetation composition in northern Chile, potentially serving as an indicator of habitat quality given its sensitivity to host plant availability. Glena bipennaria bipennaria acts as a pest species in plantation forestry, causing defoliation of economically important African mahogany trees. Natural enemies including parasitoids have been documented for G. b. bipennaria.

Glena bipennaria bipennaria has emerged as a pest of African mahogany (Khaya spp.) plantations in Brazil, causing defoliation in commercial stands. This represents a potential economic concern for plantation forestry. No other direct human interactions are documented. The genus is primarily of scientific interest for studies of host plant relationships and moth diversity in the Americas.

• Other Geometridae genera in EnnominaeSimilar wing patterns and body form; identification to genus requires examination of genitalia and specific wing venation characters not visible in field observations
• Apatelodes pandaraCo-occurs as defoliator on Khaya senegalensis in Brazil; belongs to family Apatelodidae rather than Geometridae, distinguished by different larval morphology and adult wing structure

• Geometridae
• defoliator
• pest
• host specificity
• plantation forestry
• Asteraceae
• Melioideae
• Neotropical
• Nearctic

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The Best of Denver: What to See and How to Get There During Entomology 2017
• Glena bipennaria bipennaria and Apatelodes pandara (Lepidoptera): new defoliating insects associated with Khaya in Brazil Glena bipennaria bipennaria e Apatelodes pandara (Lepidoptera): novos insetos desfolhadores associados a Khaya no Brasil
• Host plant specificity of the moth species Glena mielkei (Lepidoptera, Geometridae) in northern Chile